1. Field of the Invention
The present invention is directed to a universal X-ray device of the type having a movably suspended holder, for example a C-arm, at which a radiator for generating X-rays and a detector for receiving the X-rays are arranged.
2. Description of the Prior Art
An X-ray device of this type is disclosed, for example, in U.S. Pat. No. 5,410,584, which has a first C-arm that carries a radiation emitter at one end and a radiation detector lying opposite. The first C-arm is carried by a further, second C-arm, so as to be adjustable along its circumference via a corresponding holder.
Over the course of time, different embodiments of devices have developed in X-ray technology for the various disciplines of X-ray based examination. Thus, there are specific devices for cardangiography, general angiography, surgery, stomach/intestinal diagnostics, pulmonary diagnostics, etc.
This specialization of the devices and the necessity of keeping a multitude of different devices on hand, which involves a considerable requirement for space as well as limiting the usage of the devices and thus their economic feasibility, have resulted in the introduction of universally employable systems. The use of universal systems also has been driven by the fact that overlaps increasingly occur even among the various medical disciplines, so that the specifically designed devices for the individual applications are often too specific and thus cannot be utilized optimally at all. In this context, the system costs, particularly the costs of specific components, for example the X-ray detector, play an important part.
For cost reasons, it is also desirable not to have a number of detectors of different sizes and different designs, as is often done, but to have only a few types of detectors insofar as possible and also to employ optimally small formats, since standardization is increasingly occurring in image systems and in image processing. For small detectors, however, there is the necessity of merging or combining individual images for obtaining larger-area exposures, for which projection distortions reportedly occur in the case of known devices. Heretofore, only relatively narrow image strips having a maximum image width of approximately 5 cm were combined in a xe2x80x9cspine presentationxe2x80x9d, this in turn requiring a number of exposures, the examination time being lengthened and the device usage being reduced as a result.
An object of the present invention is to provide a universal X-ray device and a method for the operation of an X-ray device that can be unproblemmatically adapted to the various diagnostic purposes and that allow images of the detector registered next to one another to be combined error-free and undistorted to form a large image.
This object is achieved in accordance with the invention in an X-ray device wherein the radiator is mounted to a holder so as to be pivotable around at least one axis perpendicular to the plane of the holder, and that wherein the detector is displaceably mounted in the detector plane. Such an X-ray device can, for example, be constructed on the basis of a C-arm apparatus.
As a result of this mobility of the radiator and the detector at the holder, for example at the C-arm, which does not exist in conventional X-ray devices, a number of different application possibilities of such a universal X-ray device arise. The radiator is preferably pivotable toward the outside by at least 90xc2x0 relative to the connecting line to the detector, so that an inventive devicexe2x80x94in the position wherein the radiator is rotated outxe2x80x94also can be employed for exposures at a succinct type wall stand having an additional detector or film/storage foil.
In an embodiment of the invention, the radiator can be pivotable around a second axis lying in the plane of the holder, so as to be tiltable out of this plane. This two-axis pivotability can be realized by a Cardanic bearing of the radiator at the holder.
The displacement of the detector in its plane preferably is realized with the detector rotatably seated at a swivel arm that is rotatably hinged to an end of the holder such that it is displaceable in the detector plane.
The swivelling of the radiator as well as of the detector at the holder, as well as the swivelling and the displacement of the holder, preferably ensue via motorized actuators. This allows the advantageous possibility of implementing the movements of the holder, the detector and the radiator with a control unit connected thereto, so as that an error-free and undistorted combining of the images of the detector to form a large image can ensue.
The control unit can cause the combination of the radiator and detector to tilt around the rotational axis of the radiator. This does not in reality occur by a rotation and tilting of the radiator around its rotational axis, but by rotating the holder around its axis with a simultaneous displacement of the holder, so that a superimposition of the movements leads to the desired tilting around the rotational axis of the radiator. Separate adjustment of the radiator and of the detector is not required for this specific control in order to be able to merge a number of juxtaposed images without distortion.
The above object also is inventively achieved in a method wherein the detector is moved for the registration of a large-format, composite X-ray image so that it assumes exposure positions on a circular arc around the focus of the radiator, and wherein the X-ray beam of the radiator is directed onto the detector so that the central ray of the X-ray beam is perpendicularly incident on the middle of the detector.
It has proven advantageous for the detector to be displaced and aligned into the various exposure positions.
Advantageously, the radiator can be tilted or a primary radiation diaphragm can be adjusted for aligning the X-ray beam of the radiator onto the detector.